Motståndskalkylator

Decode resistor color codes, calculate series and parallel resistance, and find power dissipation. Free, fast, and easy to use.

Kalkylera

Choose a calculation type, enter your values or select color bands, and click Calculate Now to get instant results with step-by-step solutions.

Komplett användarhandbok

Vad är ett motstånd?

A resistor is an electrical component that limits or controls the flow of electric current in a circuit. Resistance is measured in ohms (Ω) and is usually shown by colored bands on the resistor body. This tool helps you decode those color bands, combine resistors in series or parallel, and calculate power dissipation — all for free.

All Formulas at a Glance

Färgkod: R = (digits) × multiplier ± tolerance%

Serie: R_total = R1 + R2 + R3 + …

Parallell: 1/R_total = 1/R1 + 1/R2 + 1/R3 + …

Driva: P = V² / R  |  I = V / R

4 Calculation Types

Färgkod

Avkoda motstånd från 4-bands, 5-bands eller 6-bands färgkoder på ett motstånd.

Seriemotstånd

Calculate total resistance when resistors are connected end to end.

Parallellt motstånd

Calculate total resistance when resistors are connected side by side.

Kraftförlust

Ta reda på hur mycket effekt ett motstånd förbrukar med spänning och resistans.

Hur man använder den här kalkylatorn

  1. Välj vad du vill beräkna — färgkod, serie, parallell eller effekt.
  2. Enter resistor values or select color bands.
  3. Välj enheter om det behövs (ohm, kilohm, megaohm).
  4. Click Calculate Now and see your answer with a step-by-step breakdown and chart.

Resistor Color Code Chart

• Black=0, Brown=1, Red=2, Orange=3, Yellow=4

• Green=5, Blue=6, Violet=7, Gray=8, White=9

• Gold multiplier = ×0.1, Silver multiplier = ×0.01

• Tolerans: Brun ±1%, Röd ±2%, Guld ±5%, Silver ±10%

Quick Examples

• Brun-Svart-Röd-Guld = 10 × 100 = 1000 Ω (1 kΩ) ±5 %

• Två 100 Ω motstånd i serie = 200 Ω

• Två 100 Ω motstånd parallellt = 50 Ω

• 12 V över 100 Ω = 1,44 W effektförlust

Viktiga anmärkningar

  • All resistance values must be greater than zero.
  • Color bands are read from left to right — the tolerance band is usually gold or silver.
  • Unit conversions are done automatically — just pick your preferred unit.
  • At least two resistors are needed for series and parallel calculations.

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